hi,

i have no idea how to compare two different engines as to their performance in a given plane

i have a .40 Partiot (prop jet) and would like to know which of the two engines would be faster:

.49 MVVS or .60 Super Tiger bluehead (from the 70's)... both engines are new, the MVVS is a ABC and the ST is ringed.

the MVVS is a speed engine, the ST is bigger but may be not have as much RPMs but can swing a bigger prop;

HOW to evaluate their comparative performance?

is there a formula for this?

i need some advice,
thanks, Vasek